Method of making dies



Sept. 17, 1935. A. F. REILLY I I METHOD OF MAKING DIES Filed Aug. 22. i931 I /N VENTO/e durable.

Patented Sept. 17, 1935 UNITEDl STATES 2,014,698 METHOD oF MAKING Dias Alfred F. Reilly, North Attleboro,` Mass., assignor to Evans Case Company, North Attleboro, Mass., a corporation of Massachusetts Application August 22, 1931, Serial No. 558,734

10 Claims.

This invention relates to a method of making dies;

, One of the objects of this invention is to provide a die construction which will be simple and Another object of this invention is to provide a device of the above character of easy and economical manufacture. Another object of this invention is to provide a device of the above character which will be highly eiiicient in operation. Another object of this invention is to provide a device of the above character whose effective surfaces will not collect foreign matter thereon. Another object of this invention is to provide a method forproducing a die of the above character which may be readily and emciently practiced with economy. Another object of this invention is to provide a method of the above character which will materially reduce the amount of labor required for producing such device. Another object is to provide a method of the above character in which the formation or collection of foreign matter upon the surface of the device during the practice of such method is substantially prevented. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts, and in the several steps and relation and order of each of the same to one or more of the others, all as will be illustratively described herein and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one or more of the various possible embodiments of the mechanical features of my invention,

Figure 1 is a front elevation partially diagrammatic, showing certain apparatus and parts in their` relation during one of the steps in my method;

Figure 2 is a plan view of a female die resulting from certain steps of my method;

Figure 3 is a front elevation showing the relation of certain parts and apparatus during another step of my method;

(Cl. 'I6-107) tain features of this invention, it might here be pointed out that in the common forms of dies, the surface thereof is to some extent adhesive and therefore has a tendency toward the collection of foreign matter which may seriously affect the suc- 5 cessful operation thereof. To alleviate this situation, after the dies have been used a few times, the operator usually has to wipe the contacting or coacting surfaces thereof to remove such matter as may have collected thereon. 'lhat this 1ois bothersome and labor wasting, will be readily understood. Furthermore, oneof the more common methods for producing such dies is to heat a piece of steel, to be formed into such a die, sumciently so that it becomes comparatively soft. 15 However, it is a characteristic of such steel, as well as other metals which may be employed for this purpose, to oxldize at the surfaces thereof when so heated and exposed to the atmosphere. These oxides generally form a heavy scale over 20 the exterior of the metal and seriously hinder if not prevent the successful promulgation of the design or imprint which is being or attempted to be f ormed thereon. Particularly great-obstacles are met with where the design is of a fine highly 25 decorative character, as in certain classes of jewelry, sheet metal cases or hollow ware, and the like. This scale becomes such a hindrance and often works suchdistortions in the design, that in the eifort to alleviate these conditions and 30- avoid discarding spoiled materials, various cumbersome and expensive expedients are resorted to. For example, the parts must be cooledduring the operation, and the scale removed therefrom before the process can be completed. One of the 35 various objects of this invention is to provide a construction for dies and a method for making such dies adapted to overcome such deflciences as above noted, as well as many others, in a practical, adequate and successful manner. 4 Referring to the drawing in detail, there is shown in Figure 1 a block l0 of metal, preferably steel, which is suitably shaped to be later mounty ed'upon a drop-hammer anvil (not illustrated) are held in any suitable manner to guard against 45 lateral displacement therefrom.` Block l0 is to be formed into the female die member, the nature of which will be more fully described hereinafter. In carrying out my process, I first chromium plate the block before its attachment to the anvil. This may be done in any convenient manner as, for example, by first copper plating the steel and next adding a chromium plate thereto, this plating process being conveniently performed by means of electroplating.- Block IU is next softened so that a design may be stamped or formed upon a surface thereof. I have found it preferable to employ steel for this die member and, in softening the steel block, I preferably heat it for a period of approximately seven hours or more at a temperature of about 2000 F. Block I0 in this heated condition is then placed upon the anvil, as described above, and attached thereto so that it presents an upper surface thereof substantially in the path of downward movement of the operative member or hub II of the drophammer (not illustrated). Upon the bottom of hub II or on the under surface thereof opposite block I0 is a design I3 which may be either imprinted or engraved therein or in relief thereon, or both. For purposes of clearer illustration, I have shown this design in relief, although it is to be understood that the design may be provided upon the metal hub II in any suitable way. Design I3 may be of any desired character, an illustrative example of which is shown at I6 in Figure 5 as will be more fully described hereinafter.

Hub I I is suiliciently weighted or appropriately driven so that it may hit block III with considerable force when released or driven from a position thereabove, and any convenient means may be'employed to cause hub II to strike block I0 repeatedly during a period of time.

As hub I I is struck against the surface of block I0, a recess I2 is formed thereon, bearing upon its base an imprint-design I4, the exact nature of which is dependent upon the character of design I3, imprinted in relief upon block I0. The hammering operation is continued until imprintdesign I4 is perfectly reproduced in recess I2, as is more clearly shown in Figure 2, Although block I0 remains red hot during this operation, no oxide or other foreign substance forms upon the surface thereof, this action being prevented by the chrome. Thus, the design may be formed perfectly in the base of recess I2 without the impediment created by the formation of these oxides. Y

When imprint-design I4, which may take any desired form, is completely reproduced in recess I2, block I0 is removed from the anvil and this removal is greatly facilitated as no sticking action between the securing parts of the anvil and the steel block can occur, due to the non-formation of any oxides on the surface thereof, as described above. The block 'with its clean surface and perfect imprint of the design as described, is then tempered in the proper manner to produce a tough interior to withstand the jars and blows incident to its use, and a hard exterior for withl standing the blows of hard material against its surface.

I have found that this hardening of the surface is further increased by the chrome plating thereon and believe this fact is due to a chrome-steel alloy being formed upon the surface. Such an action is peculiarly desirable under the circumstances, for the primary characteristic desirable in dies of this nature is the provision of a hard exterior and a tough interior. The toughness of the interior may be taken care of by suitable tempering, as described above, and the chrome alloy creates'an additional means of producing an extremely hard surface.

Upon completion of the steps described above, the female die member IIia is complete, as more clearly shown in Figure 2, and may now be used in forming a counterpart therefor or, more specifically, for forming a male die or forcer I5a (Figure 4). Thus, anotherpiece of steel, prefcrably of the same quality as block I0, is first chrome-plated in any suitable manner after which it is heated to comparative softness as described above. Referring to Figure 3, I have shown this block I5 of steel in a position immediately above the female die I Da. Block I5, the lower portion of which preferably approximates the dimensions of recess I2, is secured in this hot condition to the hammer portion of a drop-hammer in a position substantially identical to that occupied by hub II in Figure 1, Female die Illa having been firmly secured against lateral displacement upon a suitable anvil under the hammer to which the block I5 is secured as described above, the hammer and consequently block of y steel I5 is dropped with considerable force upon die I0a. over recess I2 to gradually form upon the base thereof a relief-design I6 (Figure 5) corresponding to or the reverse of imprint-design I4 1n recess I2. As this operation is continued, relief-design I6 is more perfectly outlined upon the base of block I5, and this action is facilitated by the absence of any foreign matter upon the surface thereof. Thus, as in the hereinbefore described process, no oxides may form on the surface thereof due to the chrome plating thereon.

When relief-design I6 has been clearly formed upon the base of block I5, this member is reare equal to those described in connection with l die Illa.

Under certain conditions it becomes desirable to change the sequence of certain steps in the process as outlined above and, furthermore. under certain other conditions it becomes desirable to add further steps in order to produce a superior product. For example, in some cases, re-

cess I2 in die I0a must be of such a depth that the hub I I (Figure 1) cannot sink deeply enough within the steel to produce this result in a practical manner. Thus, after the operation has progressed for a certain period of time, it is desirable to remove the block IIJ and cool it, after which excess steel may be removed from recess I2 in any desired manner. Furthermore, in certain instances even when a more shallow recess or only an indentation is sought, distortions in the steel and consequently in the design being formed therein may result, due, for example, to the expansion and contraction o'f the metal at different temperatures during the process. In such cases as these described above, for example, where the steel must be cooled during the process and certain portions of the steel removed, some of the chrome plate may be removed at the same time. In such a case, I have found it desirable to re-chrome plate the surface of the steel in a manner similar to that described above, before subjecting it again to heat. From this point, the process continues in a manner similar to that described above. This extra step of chrome plating, convenient in some instances, requires little additional labor or expense andhas many advantages, as described above.

Thus, turning to Figure 4, I have shown the completed dies in assembled condition ready for operation, both the forcer lia andrits female counterpart Illa being chrome plated. These parts may be used in any desired manner, an illustrative example of which is their use in a drop hammer such as that employed in their construction but now to stamp or form the designs borne thereby upon the material, such as parts of sheet metal cases, for example. Thus, female die I 0a is flrmly secured upon an anvil and forcer i5a is secured to the drop hammer in such a position that relief-design i6 thereof lies immediately above and is adapted to t into and register with imprint-design i4 thereof in recess i2. I have shown in Figure 5 the base of forcer lia carrying relief-design I6 imprinted thereon and, comparing this with imprint-designl i4 in recess i2 (Figure 2) it will be seen that these parts must be positioned oppositely with respect to each other so that the respective portions of the two designs interflt with` each other. With the parts inthis position, the dies may be operated to produce the required design in a piece of metal or any other suitable material placed within or over recess I2, and this operation is facilitated by the fact that the smooth surfaces of the respective dies. due to the chrome plating thereof, abhor the collection of foreign matter thereon, thus substantially eliminating the necessity of stopping the machine to clean the respective parts.

It will thus be seen that I have provided a thor-- oughly efficient and successful method of producing dies and also a practical and effective die in which the several objects described above as well as many others have been achieved in a simple, practical and economical manner.' The production of a surface for steel which will resist the collection of any foreign matter thereupon, due either to chemical reaction or outside causes during the process of making the dies and after the completion thereof when the dies are in operation. clearly aids in the reduction of wasted time and effort, thereby insuring greater economy as well as a more desirable product.

As many possible embodiments may be made of the mechanical features of the above invenfl tion and as the art herein described might be) varied in various parts, all without departing from the scope of this invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:

l. The herein described art which consists in chromium plating a piece of steel, heatingsaid piece of steel. forming a design in relief on a surface of said piece of steel while said steel is hot, cooling said steel. chromium plating said steel again. finishing said design, and tempering saidv piece of steel. l s

2. The herein described art which consists in chrome plating a piece of steel. heating said piece of steel to a softened condition, forcing a recess into said piece of steel, said recess to carry a design, removing excess steel from said recess. chrome plating said piece of steel again, reheating said piece of steel perfecting the 'design in said recess, and tempering said piece of steel.

3. The herein described a'rt which 'consists in vchromium vplating a piece of steel, heating said piece of steel, imprinting a design in a surface of said steel while said steel is hot. cooling said v piece of steel, removing excess portions of steel in the vicinity of said design, again chromium plating said piece of steel, and reheating said 5 steel.

4. The herein described art which consists in applying chromium to the surface of a piece of steel, subjecting said piece of steel to heat, shaping a figure in a surface of said piece of steel while said steel is hot, retouching said figure when said piece of steel'is cold, and tempering said piece of steel.

5. The herein described art which consists in forming a piece of steel, copper plating said piece of steel, chromium plating said piece of steel, heating said piece of steel to a relatively soft condition, forming a design in relief on a surface of said steel while said steel is in a softened condition, cooling said steel, retouching said design, copper plating :said steel again, chromium plating said steel again, and tempering said steel.

6. The herein described art which consists in chromium plating a piece of steel, heating said steel until it becomes relatively soft with respect to its original condition, imprinting a design in a surface of said steel while in said softened condition, cooling said steel, removing imperfections from said design, chromium plating said steel, and tempering said steel.

7. The herein described art which consists in chromium plating a piece of steel, heating said steel,'forming a design upon the surface of said steel to form a male die, tempering said die, chromium plating a second piece of steel, heating said second piece of steel, forcing said second piece of. steel upon saidmale die to form a design in said second piece of steel tosform a cooperating female die, and tempering said female die.

8. The herein described art which consists in copper plating a piece of steel, chrome plating said piece of steel, heating said piece of steel,im printing a design in said piece of steel while said steel is hot, removing excess steel from said de- 45 sign after said steel is cool. again chrome plating said piece of steel. and tempering said piece of steel. i

9. The herein described art which consists in copper plating a piece of steel, chrome plating 50 said piece of steel. heating said piece of steel,

-forming a design in said steel to form afemale die, enlarging the recess formed by the formation of said design, tempering said die, copper plating a second piece of steel, chrome plating said s econd piece of steel, heating said second piece of steel', forcing said second piece of steel into said die to form a design onsaid second piece of steel thus forming a cooperating male die, and tempering said male die. i 60 l0. The herein described art which consists in copper plating a piece of steel, chrome plating said piece of steel, heating said steel, forming a design in said steel to form a female die. enlars- 5 ing the recess formed bythe formation of said design, tempering said die. copperplating a second piece of steel, chrome plating said second piece of steel, heating said second piece of steel, forming. a cooperating male die by forcing said 7o second piece of steel upon said female di to im- ALFRED n. REMY. 76 

